Due to the constraints imposed by physical effects and performance degra certain limitations in sustaining the advancement of Moore’s law.Two-dimensional(2D)materials have emerged as highly promising candidates for t...Due to the constraints imposed by physical effects and performance degra certain limitations in sustaining the advancement of Moore’s law.Two-dimensional(2D)materials have emerged as highly promising candidates for the post-Moore era,offering significant potential in domains such as integrated circuits and next-generation computing.Here,in this review,the progress of 2D semiconductors in process engineering and various electronic applications are summarized.A careful introduction of material synthesis,transistor engineering focused on device configuration,dielectric engineering,contact engineering,and material integration are given first.Then 2D transistors for certain electronic applications including digital and analog circuits,heterogeneous integration chips,and sensing circuits are discussed.Moreover,several promising applications(artificial intelligence chips and quantum chips)based on specific mechanism devices are introduced.Finally,the challenges for 2D materials encountered in achieving circuit-level or system-level applications are analyzed,and potential development pathways or roadmaps are further speculated and outlooked.展开更多
The Social Internet of Things(SIoT)integrates the Internet of Things(IoT)and social networks,taking into account the social attributes of objects and diversifying the relationship between humans and objects,which over...The Social Internet of Things(SIoT)integrates the Internet of Things(IoT)and social networks,taking into account the social attributes of objects and diversifying the relationship between humans and objects,which overcomes the limitations of the IoT’s focus on associations between objects.Artificial Intelligence(AI)technology is rapidly evolving.It is critical to build trustworthy and transparent systems,especially with system security issues coming to the surface.This paper emphasizes the social attributes of objects and uses hypergraphs to model the diverse entities and relationships in SIoT,aiming to build an SIoT hypergraph generation model to explore the complex interactions between entities in the context of intelligent SIoT.Current hypergraph generation models impose too many constraints and fail to capture more details of real hypernetworks.In contrast,this paper proposes a hypergraph generation model that evolves dynamically over time,where only the number of nodes is fixed.It combines node wandering with a forest fire model and uses two different methods to control the size of the hyperedges.As new nodes are added,the model can promptly reflect changes in entities and relationships within SIoT.Experimental results exhibit that our model can effectively replicate the topological structure of real-world hypernetworks.We also evaluate the vulnerability of the hypergraph under different attack strategies,which provides theoretical support for building a more robust intelligent SIoT hypergraph model and lays the foundation for building safer and more reliable systems in the future.展开更多
Carbonate cements are the most abundant authigenic mineral and impact on physical properties greatly in sandstone reservoir.In this paper,Pinghu Formation of Xihu Sag was taken as a target.Characteristics,distribution...Carbonate cements are the most abundant authigenic mineral and impact on physical properties greatly in sandstone reservoir.In this paper,Pinghu Formation of Xihu Sag was taken as a target.Characteristics,distribution and formation of carbonate cements were investigated via optical microscopy,cathodoluminescence(CL),electron probe and in-situ carbon-oxygen isotope.The results showed that carbonate cements varied in types and shapes.Calcite/dolomite mainly present as poikilotopic cements,while ferrocalcite/ferrodolomite/ankerite generally present as pore-filling cements.Carbon isotope(δ^(13)C)values of carbonate cements were ranging from–7.77‰to–2.67‰,with an average of–4.52‰,while oxygen isotope(δ^(18)O)values were ranging from–18.94‰to–12.04‰,with an average of–14.86‰.Theδ^(13)C/δ^(18)O indicated that the paleo-fluid of carbonate cement was mainly freshwater.Organic carbon mainly came from organic matter within mature source rocks,and inorganic carbon came from dissolution of carbonate debris and early carbonate cements.Distinctiveδ^(13)C/δ^(18)O values manifest that carbonate cements with different types formed in different periods,which make different contributions to the reservoir properties.Calcite/dolomite formed during eodiagenesis(70–90℃)and early mesodiagenesis stage(90–120℃),and were favorable to reservoir owing to their compacted resistance and selective dissolution.Ferrocalcite/ferrodolomite/ankerite formed during middle-late mesodiagenetic stage(above 120℃),and were unfavorable to reservoir due to cementing the residual intergranular pores.Hence,in order to evaluate the reservoir characteristics,it is of significantly important to distinguish different types of carbonate cements and explore their origins.展开更多
Myc belongs to a family of proto-oncogenes that encode transcription factors.The overexpression of c-Myc causes many types of cancers.Recently,we established a system for screening c-Myc inhibitors and identified anti...Myc belongs to a family of proto-oncogenes that encode transcription factors.The overexpression of c-Myc causes many types of cancers.Recently,we established a system for screening c-Myc inhibitors and identified antimycin A by screening the RIKEN NPDepo chemical library.The specific mechanism of promoting tumor cell metastasis by high c-Myc expression remains to be explained.In this study,we screened approximately 5,600 microbial extracts using this system and identified a broth prepared from Streptomyces sp.RK19-A0402 strongly inhibits c-Myc transcriptional activity.After purification of the hit broth,we identified compounds closely related to the aglycone of cytovaricin and had a structure similar to that of oligomycin A.Similar to oligomycin A,the hit compounds inhibited mitochondrial complex V.The mitochondria dysfunction caused by the compounds induced the production of reactive oxygen species(ROS),and the ROS activated GSK3α/βthat phosphorylated c-Myc for ubiquitination.This study provides a successful screening strategy for identifying natural products as potential c-Myc inhibitors as potential anticancer agents.展开更多
Background Serotonin is an important signaling molecule that regulates secretory and sensory functions in the gut.Gut microbiota has been demonstrated to affect serotonin synthesis in rodent models.However,how gut mic...Background Serotonin is an important signaling molecule that regulates secretory and sensory functions in the gut.Gut microbiota has been demonstrated to affect serotonin synthesis in rodent models.However,how gut microbes regulate intestinal serotonin production in piglets remains vague.To investigate the relationship between microbiota and serotonin specifically in the colon,microbial composition and serotonin concentration were analyzed in ileum-cannulated piglets subjected to antibiotic infusion from the ileum when comparing with saline infusion.Microbes that correlated positively with serotonin production were isolated from piglet colon and were further used to investi-gate the regulation mechanisms on serotonin production in IPEC-J2 and a putative enterochromaffin cell line RIN-14B cells.Results Antibiotic infusion increased quantities of Lactobacillus amylovorus(LA)that positively correlated with increased serotonin concentrations in the colon,while no effects observed for Limosilactobacillus reuteri(LR).To understand how microbes regulate serotonin,representative strains of LA,LR,and Streptococcus alactolyticus(SA,enriched in feces from prior observation)were selected for cell culture studies.Compared to the control group,LA,LR and SA supernatants significantly up-regulated tryptophan hydroxylase 1(TPH1)expression and promoted serotonin production in IPEC-J2 cells,while in RIN-14B cells only LA exerted similar action.To investigate potential mechanisms mediated by microbe-derived molecules,microbial metabolites including lactate,acetate,glutamine,andγ-aminobutyric acid were selected for cell treatment based on computational and metabolite profiling in bacte-rial supernatant.Among these metabolites,acetate upregulated the expression of free fatty acid receptor 3 and TPH1 while downregulated indoleamine 2,3-dioxygenase 1.Similar effects were also recapitulated when treating the cells with AR420626,an agonist targeting free fatty acid receptor 3.Conclusions Overall,these results suggest that Lactobacillus amylovorus showed a positive correlation with sero-tonin production in the pig gut and exhibited a remarkable ability to regulate serotonin production in cell cultures.These findings provide evidence that microbial metabolites mediate the dialogue between microbes and host,which reveals a potential approach using microbial manipulation to regulate intestinal serotonin biosynthesis.展开更多
Hierarchical SAPO‐34 crystals were synthesized by a facile acid etching post‐treatment. Butterfly‐shaped porous patterns on four side faces and hierarchical pores composed of micropores,mesopores and macropores wer...Hierarchical SAPO‐34 crystals were synthesized by a facile acid etching post‐treatment. Butterfly‐shaped porous patterns on four side faces and hierarchical pores composed of micropores,mesopores and macropores were formed after a nitric acid or oxalic acid treatment. The catalyticperformance of the hierarchical SAPO‐34 for the methanol to olefins (MTO) process showed that thesynergistic effect of the hierarchical pores and acid sites resulted in a longer catalyst lifetime (from210 to 390 min for the acid treated SAPO‐34) and higher selectivity to light olefins of 92%–94%.The ethylene selectivity can be adjusted between 37.4% and 51.5% by the pore size. No hierarchical SAPO‐34 was obtained after a treatment with butanedioic acid, and with this sample, fast deactivation was detected after 100 min.展开更多
Combining 3D printing with precursor-derived ceramic for fabricating electromagnetic(EM) wave-absorbing metamaterials has attracted great attention. This study presents a novel ultraviolet-curable polysiloxane precurs...Combining 3D printing with precursor-derived ceramic for fabricating electromagnetic(EM) wave-absorbing metamaterials has attracted great attention. This study presents a novel ultraviolet-curable polysiloxane precursor for digital light processing(DLP) 3D printing to fabricate ceramic parts with complex geometry, no cracks and linear shrinkage. Guiding with the principles of impedance matching, attenuation, and effective-medium theory, we design a crosshelix-array metamaterial model based on the complex permittivity constant of precursor-derived ceramics. The corresponding ceramic metamaterials can be successfully prepared by DLP printing and subsequent pyrolysis process, achieving a low reflection coefficient and a wide effective absorption bandwidth in the X-band even under high temperature. This is a general method that can be extended to other bands, which can be realized by merely adjusting the unit structure of meta-materials. This strategy provides a novel and effective avenue to achieve “target-design-fabricating” ceramic metamaterials, and it exposes the downstream applications of highly efficient and broad EM wave-absorbing materials and structures with great potential applications.展开更多
The repair of osteochondral defects is one of the major clinical challenges in orthopaedics.Well-established osteochondral tissue engineering methods have shown promising results for the early treatment of small defec...The repair of osteochondral defects is one of the major clinical challenges in orthopaedics.Well-established osteochondral tissue engineering methods have shown promising results for the early treatment of small defects.However,less success has been achieved for the regeneration of large defects,which is mainly due to the mechanical environment of the joint and the heterogeneous nature of the tissue.In this study,we developed a multi-layered osteochondral scaffold to match the heterogeneous nature of osteochondral tissue by harnessing additive manufacturing technologies and combining the established art laser sintering and material extrusion techniques.The developed scaffold is based on a titanium and polylactic acid matrix-reinforced collagen“sandwich”composite system.The microstructure and mechanical properties of the scaffold were examined,and its safety and efficacy in the repair of large osteochondral defects were tested in an ovine condyle model.The 12-week in vivo evaluation period revealed extensive and significantly higher bone in-growth in the multi-layered scaffold compared with the collagen–HAp scaffold,and the achieved stable mechanical fixation provided strong support to the healing of the overlying cartilage,as demonstrated by hyaline-like cartilage formation.The histological examination showed that the regenerated cartilage in the multi-layer scaffold group was superior to that formed in the control group.Chondrogenic genes such as aggrecan and collagen-II were upregulated in the scaffold and were higher than those in the control group.The findings showed the safety and efficacy of the cell-free“translation-ready”osteochondral scaffold,which has the potential to be used in a one-step surgical procedure for the treatment of large osteochondral defects.展开更多
Plant glandular trichomes(GTs)are epidermal outgrowths with the capacity to biosynthesize and secrete specialized metabolites,that are of great scientific and practical significance.Our understanding of the developmen...Plant glandular trichomes(GTs)are epidermal outgrowths with the capacity to biosynthesize and secrete specialized metabolites,that are of great scientific and practical significance.Our understanding of the developmental process of GTs is limited,and no single plant species serves as a unique model.Here,we review the genetic mechanisms of GT initiation and development and provide a summary of the biosynthetic pathways of GT-specialized metabolites in nonmodel plant species,especially horticultural crops.We discuss the morphology and classification of GT types.Moreover,we highlight technological advancements in methods employed for investigating GTs.Understanding the molecular basis of GT development and specialized metabolites not only offers useful avenues for research in plant breeding that will lead to the improved production of desirable metabolites,but also provides insights for plant epidermal development research.展开更多
Osteoarthritis (OA), identified as one of the priorities for the Bone and Joint Decade, is one of the most prevalent joint diseases, which causes pain and disability of joints in the adult population. Secondary OA u...Osteoarthritis (OA), identified as one of the priorities for the Bone and Joint Decade, is one of the most prevalent joint diseases, which causes pain and disability of joints in the adult population. Secondary OA usually stems from repetitive overloading to the osteochondral (OC) unit, which could result in cartilage damage and changes in the subchondral bone, leading to mechanical instability of the joint and loss of joint function. Tissue engineering approaches have emerged for the repair of cartilage defects and damages to the subchondral bone in the early stages of OA and have shown potential in restoring the joint's function. In this approach, the use of three-dimensional scaffolds (with or without cells) provides support for tissue growth. Commercially available OC scaffolds have been studied in OA patients for repair and regeneration of OC defects. However, none of these scaffolds has shown satisfactory clinical results. This article reviews the OC tissue structure and the design, manufacturing and performance of current OC scaffolds in treatment of OA. The findings demonstrate the importance of biological and biomechanical fixations of OC scaffolds to the host tissue in achieving an improved cartilage fill and a hyaline-like tissue formation. Achieving a strong and stable subchondral bone support that helps the regeneration of overlying cartilage seems to be still a grand challenge for the early treatment of OA.展开更多
To get an optimal product of orthopaedic implant or regenerative medicine needs to follow trialand-error analyses to investigate suitable product’s material,structure,mechanical properites etc.The whole process from ...To get an optimal product of orthopaedic implant or regenerative medicine needs to follow trialand-error analyses to investigate suitable product’s material,structure,mechanical properites etc.The whole process from in vivo tests to clinical trials is expensive and time-consuming.Computational model is seen as a useful analysis tool to make the product development.A series of models for simulating tissue engineering process from cell attachment to tissue regeneration are reviewed.The challenging is that models for simulating tissue engineering processes are developed separately.From cell to tissue regeneration,it would go through blood injection after moving out the defect;to cell disperse and attach on the scaffold;to proliferation,migration and differentiation;and to the final part-becoming mature tissues.This paper reviewed models that related to tissue engineering process,aiming to provide an opportunity for researchers to develop a mature model for whole tissue engineering process.This article focuses on the model analysis methods of cell adhesion,nutrient transport and cell proliferation,differentiation and migration in tissue engineering.In cell adhesion model,one of the most accurate method is to use discrete phase model to govern cell movement and use Stanton-Rutland model for simulating cell attachment.As for nutrient transport model,numerical model coupling with volume of fluid model and species transport model together is suitable for predicting nutrient transport process.For cell proliferation,differentiation and migration,finite element method with random-walk algorithm is one the most advanced way to simulate these processes.Most of the model analysis methods require further experiments to verify the accuracy and effectiveness.Due to the lack of technology to detect the rate of nutrient diffusion,there are especially few researches on model analysis methods in the area of blood coagulation.Therefore,there is still a lot of work to be done in the research of the whole process model method of tissue engineering.In the future,the numerical model would be seen as an optimal way to investigate tissue engineering products bioperformance and also enable to optimize the parameters and material types of the tissue engineering products.展开更多
Faraday isolators can prevent the front-end system from disturbance and damage caused by a back-reflected beam,so they are important elements in laser systems.As magneto-optical materials are the most important compon...Faraday isolators can prevent the front-end system from disturbance and damage caused by a back-reflected beam,so they are important elements in laser systems.As magneto-optical materials are the most important component in Faraday isolators,the studies on magneto-optical materials have attracted much attention these years.Tb_(3)Al_(5)O_(12)(TAG)ceramics are considered to be one of the most promising magneto-optical materials for visible to near-infrared wavelength band application because of their outstanding comprehensive magneto-optical performance.However,the optical quality of TAG ceramics needs further optimization to meet the application requirements.In this work,high optical quality(Tb_(1−x)Y_(x))_(3)Al_(5)O_(12)(x=0,0.05,0.1,0.2,and 0.3)magneto-optical ceramics were fabricated successfully by solid-state reaction sintering combined with hot isostatic pressing(HIP)post-treatment.All the ceramics obtained showed a single garnet phase for different values of x in the range studied.The addition of Y_(2)O_(3) was found to suppress the secondary phase and improve optical quality significantly.The ceramic samples obtained had clear grain boundaries and possessed the in-line transmittance values of 82.9%at 1064 nm and 82.2%at 633 nm,respectively.The Verdet constants of(Tb_(1−x)Y_(x))_(3)Al_(5)O_(12)ceramics with x=0,0.05,0.1,0.2,and 0.3 were−188.1,−175.4,−168.5,−143.0,and−119.9 rad/(T·m),respectively.The thermal conductivity of TAG ceramics was found to be 5.23 W/(m·K)at 25℃,and when 20%Y was substituted in place of Tb,the thermal conductivity decreased by only 9.4%.展开更多
Two-dimensional(2D)tungsten selenide(WSe_(2))is promising candidate material for future electronic applications,owing to its potential for ultimate device scaling.For improving the electronic performance of WSe_(2)-ba...Two-dimensional(2D)tungsten selenide(WSe_(2))is promising candidate material for future electronic applications,owing to its potential for ultimate device scaling.For improving the electronic performance of WSe_(2)-based field-effect transistors(FETs),the modification of surface properties is essential.In this study,the seamless structural phase transition in WSe_(2) lattice is achieved by soft oxygen plasma,regulating the electrical conductance of WSe_(2)-based FETs.We found that during the soft oxygen plasma treatment with optimal processing time,the generated oxygen ions can substitute some selenium atoms and thus locally modify the bond length,inducing 2H→1T phase transition in WSe_(2) with seamless interfaces.The mosaic structures have been proven to tailor the electronic structure and increase the hole carrier concentration inside WSe_(2),significantly increasing the channel conductance of WSe_(2) FETs.With the further increase of the oxygen plasma treatment time,the creation of more selenium vacancy defects leads to the electronic doping,resulting in the reduction of conductance.Benefiting from the hexagonal boron nitride(h-BN)encapsulation to interrupt the partial structural relaxation from 1T to 2H phase,our WSe_(2) FET exhibits high electronic stability with conductance of 6.8×10^(-4) S,which is about four orders of magnitude higher than 2H WSe_(2)(5.8×10^(-8) S).This study could further broaden the WSe_(2) FETs in applications for functionalization and integration in electronics.展开更多
Climate change is an important issue facing the world today and carbon reduction has become the fo-cus of attention for all countries.Alternative bio-fuels are an important means to achieve carbon emis-sion reduction....Climate change is an important issue facing the world today and carbon reduction has become the fo-cus of attention for all countries.Alternative bio-fuels are an important means to achieve carbon emis-sion reduction.The production of jet fuel precursors from biomass by hydrothermal liquefaction(HTL)has received a lot of attention due to its mild conditions and environmental friendliness.Lignocellulosic biomass and algal biomass are considered as the second and the third generation biomasses as promising raw materials for alternative fuel preparation.Among them,lignocellulosic biomass has been extensively studied due to its wide range of sources and can be divided into one-step HTL and stepwise HTL accord-ing to the process method.Algal biomass has been extensively studied experimentally due to its short growth cycle and the fact that it can sequester large amounts of carbon without taking up arable land.In this paper,the feedstock composition of different biomasses is reviewed for the HTL of biomass.A detailed review of the process characteristics,reaction pathways and influencing factors for the HTL pro-duction of jet fuel precursors from lignocellulosic biomass and algal biomass is also presented.Theoretical references are provided for further process optimization and bio-crude quality upgrading.展开更多
Inactivated coronavirus disease 2019(COVID-19)vaccines such as CoronaVac and BBIBP-CorV have been widely used in China.However,more investigation is still needed to understand antibodies'duration and effectiveness...Inactivated coronavirus disease 2019(COVID-19)vaccines such as CoronaVac and BBIBP-CorV have been widely used in China.However,more investigation is still needed to understand antibodies'duration and effectiveness against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)variants in the real world.In this study,575 participants who had been vaccinated with two or three doses of the inactivated vaccine were recruited.Serum samples were collected and tested for anti-spike IgG and neutralizing antibodies against SARS-CoV-2(original strain,Dela,and Omicron).Unsurprisingly,a third dose of the vaccine significantly enhanced antibody responses against SARS-CoV-2 and its variants.However,despite a booster dose,the neutralizing antibody levels against Omicron,particularly the BA.5.2 subvariant,remained low.There was no sex bias,but an age bias was observed.Notably,the predominant IgG subclass antibodies were IgG1 and IgG2,with a much lower level of IgG4.After the booster shot,the ratio of IgG4 to IgG1 significantly increased.The observation of IgG1 to the IgG4 class switch after repeated inactivated vaccinations underscores the importance of continuous monitoring of subclass antibody responses.Further clinical investigations are required to understand the implications of this class switch for optimizing immunization strategies.展开更多
At present,phase change materials(PCMs)with single function hardly meet the needs of advanced intelligent materials in practical applications,and the multifunction integration is the current trend.However,photo-cured ...At present,phase change materials(PCMs)with single function hardly meet the needs of advanced intelligent materials in practical applications,and the multifunction integration is the current trend.However,photo-cured multifunctional PCMs are hampered by insufficient transparency due to adding functional fillers,such as carbon and metal materials.The novel strategy is necessary to overcome this limitation.Here,a photo-cured multifunctional PCM is prepared by using the design of a lamellar structure composing the photo-cured phase change polymer layer and the functional fillers layer.The curing of the phase change polymer is realized by the photo-induced"thiol-ene"click reaction,and reversible dynamic disulfide bonds are introduced into the PCM,which not only gives the phase change crosslinked network reprocessability,but also strengthens the interface layer by the chain rearrangement to form a stable composite structure.The carboxylated multiwalled carbon nanotubes(CCNTs)and silver nanowires(AgNWs),as functional fillers,give the PCM photo-thermal conversion,self-cleaning and electromagnetic shielding(EMI SE)performances.Its phase change latent heat and photo-thermal conversion can reach 105.2 J/g and 78.5%,and the water contact angle is 142°with self-cleaning performance.In addition,due to the dense and well-developed conductive path formed by AgNWs layer on the PCM surface,the EMI SE effect can reach 39 dB with only 6.3%(in mass)filler content and 7.2%phase change latent heat loss.As far as we know,this is the first report about photo-cured PCMs with self-cleaning,photo-thermal conversion and EMI SE performances.展开更多
Supersonic aircraft requires thermal endurance of aviation fuel in the process of cooling engine and aircraft. As the composition of petroleum-based jet fuel (RP-3) is confined by crude oil and refining process, susta...Supersonic aircraft requires thermal endurance of aviation fuel in the process of cooling engine and aircraft. As the composition of petroleum-based jet fuel (RP-3) is confined by crude oil and refining process, sustainable alternative jet fuel with green house gas reduction become to undertake the composition optimization for improving thermal stability. For designing aviation fuel with robust thermal stability and the detail understanding of thermal stability mechanism, RP-3, Fischer–Tropsch fuel, and additives with cyclic structure for absorbing free radical, were investigated thermal stability by modifying different blend ratios under different conditions. Thermal endurance degree was assessed by chroma and deposition tendency. FT blend with cyclic hydrocarbon can improve thermal endurance degree. In compliance with individual optimized blend ratio, the contribution follows methyl cyclopentane > decalin > methyl cyclohexane > tetralin > n-propyl-benzene > 1,2,4 trimethyl-benzene. The appropriate blend ratio could undertake hydrogen donors for terminating the propagation of oxygen-carrying radical, but hydrocarbons with cyclic structure could enhance deposition tendency. Methyl cyclopentane and its oxidation derivatives take the roles of solvent by anti-polymerization and hydrogen donor by opening cyclic structure in the thermal endurance process, and thus lead to a wide range of blend ratio for improving significantly thermal stability. β-scission leading to C–C bond cleavage is the major reaction at the early decomposition stage, which resulted in most abundant derivatives plus C2. The effects of additives on thermal stability are complex and nonlinear on the tendency of thermal deposits and thermal endurance degree, and thus the appropriate ANN-thermal stability model has been trained based on the experiment data and can achieve above 0.995 correlation coefficient. ANN - thermal stability model can predict not only the content of derivatives including ester, olefin, alcohol, ketone, cyclic oxide, aromatics but also the degree of thermal endurance.展开更多
Wire electrochemical machining(WECM) is a flexible and effective method for machining complex-shaped metal components, but the ability to machine large-thickness workpieces is hampered by the difficulty of transportin...Wire electrochemical machining(WECM) is a flexible and effective method for machining complex-shaped metal components, but the ability to machine large-thickness workpieces is hampered by the difficulty of transporting electrolytic products in the narrow machining gap. This paper proposes a novel hybrid machining technique that combines the characteristics of WECM and wire electric discharge machining(WEDM), namely, helical wire electrochemical discharge machining. The formation mechanism of electrical discharge in salt-glycol solution was elucidated.Experiments and simulation were conducted to verify the machining mechanism and investigate the performance of the proposed technique. The results show that as the recast layer can be removed by electrochemical action during the proposed process, the surface quality is effectively improved.Minimum surface roughness of the slit sidewall after machining reaches Ra= 0.12 μm. Minimum standard deviation of the slit after machining reaches 5 μm. Moreover, the existence of the discharges significantly improves the transport of the electrolytic products, thus ensuring high machining efficiency. In the experiments, the maximum feed rate of the helical wire electrochemical discharge machining reaches 7 μm/s(12.6 mm^(2)/min). Finally, mortise structures of Inconel 718 with good machining accuracy and surface quality are fabricated with a feed rate of 5 μm/s(9 mm^(2)/min),demonstrating that electrical discharge assisted helical wire ECM is a promising technique for machining large-thickness hard metal materials.展开更多
Hepatocellular carcinoma(HCC)is one of the most common malignancies and a leading cause of cancer-related death worldwide.Surgery remains the primary and most successful therapy option for the treatment of early-and m...Hepatocellular carcinoma(HCC)is one of the most common malignancies and a leading cause of cancer-related death worldwide.Surgery remains the primary and most successful therapy option for the treatment of early-and mid-stage HCCs,but the high heterogeneity of HCC renders prognostic prediction challenging.The construction of relevant prognostic models helps to stratify the prognosis of surgically treated patients and guide personalized clinical decision-making,thereby improving patient survival rates.Currently,the prognostic assessment of HCC is based on several commonly used staging systems,such as Tumor-Node-Metastasis(TNM),Cancer of the Liver Italian Program(CLIP),and Barcelona Clinic Liver Cancer(BCLC).Given the insufficiency of these staging systems and the aim to improve the accuracy of prognostic prediction,researchers have incorporated further prognostic factors,such as microvascular infiltration,and proposed some new prognostic models for HCC.To provide insights into the prospects of clinical oncology research,this review describes the commonly used HCC staging systems and new models proposed in recent years.展开更多
Electron-correlated materials have been drawing ever-increasing attention due to their fascinating physical behaviors and extensive application scenarios.In this review,a new method for material research and design(R&...Electron-correlated materials have been drawing ever-increasing attention due to their fascinating physical behaviors and extensive application scenarios.In this review,a new method for material research and design(R&D),named structural-functional unit ordering(SFU ordering),which is presented,overcomes the shortcomings—for example,the limitation of finite chemical elements and long R&D circle-of conventional strategy and thus provides guidance for the design of these high-performance functional materials on demand.Meanwhile,with the development of material characterization technologies,SFUs of different scales and types can be directly observed,which,moreover,regulate the corresponding orderings.The review,starts with an introduction of the profile for SFU ordering and the synergistic effect between SFUs.Then,studies on several new high-performance electronic-correlated materials,for example,a ferromagnetic semiconductor with local spin,ferromagnetic metals with spin topologies,ferroelectric thin films with polar topologies,piezoelectric thin films with nanopillars enclosed by charged boundaries,thermoelectric materials with local ferromagnetic nanoparticles and topotactic phase transformation with conducting nanofilaments are stated in detail one by one.The vital aspect is the breaking of local symmetry,the construction,the structure,of SFUs and their orderings existing or theoretically existing,together with the enhanced/new performance.All in all,the main comments of the review tend to the remaining challenges,promising design approaches for the SFUs,and their orderings for high-performance functional materials.展开更多
基金supported in part by STI 2030-Major Projects under Grant 2022ZD0209200sponsored by Tsinghua-Toyota Joint Research Fund+12 种基金in part by National Natural Science Foundation of China under Grant 62374099, Grant 62022047, Grant U20A20168, Grant 51861145202, Grant 51821003, and Grant 62175219in part by the National Key R&D Program under Grant 2016YFA0200400in part by Beijing Natural Science-Xiaomi Innovation Joint Fund Grant L233009in part supported by Tsinghua University-Zhuhai Huafa Industrial Share Company Joint Institute for Architecture Optoelectronic Technologies (JIAOT KF202204)in part by the Daikin-Tsinghua Union Programin part sponsored by CIE-Tencent Robotics X Rhino-Bird Focused Research Programin part by the Guoqiang Institute, Tsinghua Universityin part by the Research Fund from Beijing Innovation Center for Future Chipin part by Shanxi “1331 Project” Key Subjects Constructionin part by the Youth Innovation Promotion Association of Chinese Academy of Sciences (2019120)the opening fund of Key Laboratory of Science and Technology on Silicon Devices, Chinese Academy of Sciencesin part by the project of MOE Innovation Platformin part by the State Key Laboratory of Integrated Chips and Systems
文摘Due to the constraints imposed by physical effects and performance degra certain limitations in sustaining the advancement of Moore’s law.Two-dimensional(2D)materials have emerged as highly promising candidates for the post-Moore era,offering significant potential in domains such as integrated circuits and next-generation computing.Here,in this review,the progress of 2D semiconductors in process engineering and various electronic applications are summarized.A careful introduction of material synthesis,transistor engineering focused on device configuration,dielectric engineering,contact engineering,and material integration are given first.Then 2D transistors for certain electronic applications including digital and analog circuits,heterogeneous integration chips,and sensing circuits are discussed.Moreover,several promising applications(artificial intelligence chips and quantum chips)based on specific mechanism devices are introduced.Finally,the challenges for 2D materials encountered in achieving circuit-level or system-level applications are analyzed,and potential development pathways or roadmaps are further speculated and outlooked.
文摘The Social Internet of Things(SIoT)integrates the Internet of Things(IoT)and social networks,taking into account the social attributes of objects and diversifying the relationship between humans and objects,which overcomes the limitations of the IoT’s focus on associations between objects.Artificial Intelligence(AI)technology is rapidly evolving.It is critical to build trustworthy and transparent systems,especially with system security issues coming to the surface.This paper emphasizes the social attributes of objects and uses hypergraphs to model the diverse entities and relationships in SIoT,aiming to build an SIoT hypergraph generation model to explore the complex interactions between entities in the context of intelligent SIoT.Current hypergraph generation models impose too many constraints and fail to capture more details of real hypernetworks.In contrast,this paper proposes a hypergraph generation model that evolves dynamically over time,where only the number of nodes is fixed.It combines node wandering with a forest fire model and uses two different methods to control the size of the hyperedges.As new nodes are added,the model can promptly reflect changes in entities and relationships within SIoT.Experimental results exhibit that our model can effectively replicate the topological structure of real-world hypernetworks.We also evaluate the vulnerability of the hypergraph under different attack strategies,which provides theoretical support for building a more robust intelligent SIoT hypergraph model and lays the foundation for building safer and more reliable systems in the future.
文摘Carbonate cements are the most abundant authigenic mineral and impact on physical properties greatly in sandstone reservoir.In this paper,Pinghu Formation of Xihu Sag was taken as a target.Characteristics,distribution and formation of carbonate cements were investigated via optical microscopy,cathodoluminescence(CL),electron probe and in-situ carbon-oxygen isotope.The results showed that carbonate cements varied in types and shapes.Calcite/dolomite mainly present as poikilotopic cements,while ferrocalcite/ferrodolomite/ankerite generally present as pore-filling cements.Carbon isotope(δ^(13)C)values of carbonate cements were ranging from–7.77‰to–2.67‰,with an average of–4.52‰,while oxygen isotope(δ^(18)O)values were ranging from–18.94‰to–12.04‰,with an average of–14.86‰.Theδ^(13)C/δ^(18)O indicated that the paleo-fluid of carbonate cement was mainly freshwater.Organic carbon mainly came from organic matter within mature source rocks,and inorganic carbon came from dissolution of carbonate debris and early carbonate cements.Distinctiveδ^(13)C/δ^(18)O values manifest that carbonate cements with different types formed in different periods,which make different contributions to the reservoir properties.Calcite/dolomite formed during eodiagenesis(70–90℃)and early mesodiagenesis stage(90–120℃),and were favorable to reservoir owing to their compacted resistance and selective dissolution.Ferrocalcite/ferrodolomite/ankerite formed during middle-late mesodiagenetic stage(above 120℃),and were unfavorable to reservoir due to cementing the residual intergranular pores.Hence,in order to evaluate the reservoir characteristics,it is of significantly important to distinguish different types of carbonate cements and explore their origins.
基金supported by grants from JSPS/MEXT KAKENHI(JP19H05302 and JP21H00295 to N.W.)the MOST-RIKEN Collaboration Project(2021YFE0108000 to J.L.and N.W.)Translation Research Programs from Fukushima Prefecture(to K.S.).
文摘Myc belongs to a family of proto-oncogenes that encode transcription factors.The overexpression of c-Myc causes many types of cancers.Recently,we established a system for screening c-Myc inhibitors and identified antimycin A by screening the RIKEN NPDepo chemical library.The specific mechanism of promoting tumor cell metastasis by high c-Myc expression remains to be explained.In this study,we screened approximately 5,600 microbial extracts using this system and identified a broth prepared from Streptomyces sp.RK19-A0402 strongly inhibits c-Myc transcriptional activity.After purification of the hit broth,we identified compounds closely related to the aglycone of cytovaricin and had a structure similar to that of oligomycin A.Similar to oligomycin A,the hit compounds inhibited mitochondrial complex V.The mitochondria dysfunction caused by the compounds induced the production of reactive oxygen species(ROS),and the ROS activated GSK3α/βthat phosphorylated c-Myc for ubiquitination.This study provides a successful screening strategy for identifying natural products as potential c-Myc inhibitors as potential anticancer agents.
基金the Natural Science Foundation of China(31902166,32030104).
文摘Background Serotonin is an important signaling molecule that regulates secretory and sensory functions in the gut.Gut microbiota has been demonstrated to affect serotonin synthesis in rodent models.However,how gut microbes regulate intestinal serotonin production in piglets remains vague.To investigate the relationship between microbiota and serotonin specifically in the colon,microbial composition and serotonin concentration were analyzed in ileum-cannulated piglets subjected to antibiotic infusion from the ileum when comparing with saline infusion.Microbes that correlated positively with serotonin production were isolated from piglet colon and were further used to investi-gate the regulation mechanisms on serotonin production in IPEC-J2 and a putative enterochromaffin cell line RIN-14B cells.Results Antibiotic infusion increased quantities of Lactobacillus amylovorus(LA)that positively correlated with increased serotonin concentrations in the colon,while no effects observed for Limosilactobacillus reuteri(LR).To understand how microbes regulate serotonin,representative strains of LA,LR,and Streptococcus alactolyticus(SA,enriched in feces from prior observation)were selected for cell culture studies.Compared to the control group,LA,LR and SA supernatants significantly up-regulated tryptophan hydroxylase 1(TPH1)expression and promoted serotonin production in IPEC-J2 cells,while in RIN-14B cells only LA exerted similar action.To investigate potential mechanisms mediated by microbe-derived molecules,microbial metabolites including lactate,acetate,glutamine,andγ-aminobutyric acid were selected for cell treatment based on computational and metabolite profiling in bacte-rial supernatant.Among these metabolites,acetate upregulated the expression of free fatty acid receptor 3 and TPH1 while downregulated indoleamine 2,3-dioxygenase 1.Similar effects were also recapitulated when treating the cells with AR420626,an agonist targeting free fatty acid receptor 3.Conclusions Overall,these results suggest that Lactobacillus amylovorus showed a positive correlation with sero-tonin production in the pig gut and exhibited a remarkable ability to regulate serotonin production in cell cultures.These findings provide evidence that microbial metabolites mediate the dialogue between microbes and host,which reveals a potential approach using microbial manipulation to regulate intestinal serotonin biosynthesis.
基金supported by the National Natural Science Foundation of China (21403279, 21507141, 21506243)the Science and Technology Commission of Shanghai Municipality (14DZ1207602, 14DZ1203700)~~
文摘Hierarchical SAPO‐34 crystals were synthesized by a facile acid etching post‐treatment. Butterfly‐shaped porous patterns on four side faces and hierarchical pores composed of micropores,mesopores and macropores were formed after a nitric acid or oxalic acid treatment. The catalyticperformance of the hierarchical SAPO‐34 for the methanol to olefins (MTO) process showed that thesynergistic effect of the hierarchical pores and acid sites resulted in a longer catalyst lifetime (from210 to 390 min for the acid treated SAPO‐34) and higher selectivity to light olefins of 92%–94%.The ethylene selectivity can be adjusted between 37.4% and 51.5% by the pore size. No hierarchical SAPO‐34 was obtained after a treatment with butanedioic acid, and with this sample, fast deactivation was detected after 100 min.
基金supported by the National Science Fund for Distinguished Young Scholars(52025034)National Natural Science Foundation of China(21975204)Innovation Team of Shaanxi Sanqin Scholars。
文摘Combining 3D printing with precursor-derived ceramic for fabricating electromagnetic(EM) wave-absorbing metamaterials has attracted great attention. This study presents a novel ultraviolet-curable polysiloxane precursor for digital light processing(DLP) 3D printing to fabricate ceramic parts with complex geometry, no cracks and linear shrinkage. Guiding with the principles of impedance matching, attenuation, and effective-medium theory, we design a crosshelix-array metamaterial model based on the complex permittivity constant of precursor-derived ceramics. The corresponding ceramic metamaterials can be successfully prepared by DLP printing and subsequent pyrolysis process, achieving a low reflection coefficient and a wide effective absorption bandwidth in the X-band even under high temperature. This is a general method that can be extended to other bands, which can be realized by merely adjusting the unit structure of meta-materials. This strategy provides a novel and effective avenue to achieve “target-design-fabricating” ceramic metamaterials, and it exposes the downstream applications of highly efficient and broad EM wave-absorbing materials and structures with great potential applications.
基金financially supported by the Versus Arthritis (No. 21160)the Rosetree Trust (No. A1184)+2 种基金the European Commission via H2020-MSCA-RISE Program (BAMOS Project (No.734156))Innovate UK via Newton Fund (No. 102872)the Engineering and Physical Science Research Council (EPSRC) via DTP Case Programme (No. EP/T517793/1)
文摘The repair of osteochondral defects is one of the major clinical challenges in orthopaedics.Well-established osteochondral tissue engineering methods have shown promising results for the early treatment of small defects.However,less success has been achieved for the regeneration of large defects,which is mainly due to the mechanical environment of the joint and the heterogeneous nature of the tissue.In this study,we developed a multi-layered osteochondral scaffold to match the heterogeneous nature of osteochondral tissue by harnessing additive manufacturing technologies and combining the established art laser sintering and material extrusion techniques.The developed scaffold is based on a titanium and polylactic acid matrix-reinforced collagen“sandwich”composite system.The microstructure and mechanical properties of the scaffold were examined,and its safety and efficacy in the repair of large osteochondral defects were tested in an ovine condyle model.The 12-week in vivo evaluation period revealed extensive and significantly higher bone in-growth in the multi-layered scaffold compared with the collagen–HAp scaffold,and the achieved stable mechanical fixation provided strong support to the healing of the overlying cartilage,as demonstrated by hyaline-like cartilage formation.The histological examination showed that the regenerated cartilage in the multi-layer scaffold group was superior to that formed in the control group.Chondrogenic genes such as aggrecan and collagen-II were upregulated in the scaffold and were higher than those in the control group.The findings showed the safety and efficacy of the cell-free“translation-ready”osteochondral scaffold,which has the potential to be used in a one-step surgical procedure for the treatment of large osteochondral defects.
基金This study was supported by the National Natural Science Foundation of China(32020103014)Project of Beijing Agricultural Innovation Consortium(BAIC01)The Construction of Beijing Science and Technology Innovation and Service Capacity in Top Subjects(CEFF-PXM2019_014207_000032).
文摘Plant glandular trichomes(GTs)are epidermal outgrowths with the capacity to biosynthesize and secrete specialized metabolites,that are of great scientific and practical significance.Our understanding of the developmental process of GTs is limited,and no single plant species serves as a unique model.Here,we review the genetic mechanisms of GT initiation and development and provide a summary of the biosynthetic pathways of GT-specialized metabolites in nonmodel plant species,especially horticultural crops.We discuss the morphology and classification of GT types.Moreover,we highlight technological advancements in methods employed for investigating GTs.Understanding the molecular basis of GT development and specialized metabolites not only offers useful avenues for research in plant breeding that will lead to the improved production of desirable metabolites,but also provides insights for plant epidermal development research.
文摘Osteoarthritis (OA), identified as one of the priorities for the Bone and Joint Decade, is one of the most prevalent joint diseases, which causes pain and disability of joints in the adult population. Secondary OA usually stems from repetitive overloading to the osteochondral (OC) unit, which could result in cartilage damage and changes in the subchondral bone, leading to mechanical instability of the joint and loss of joint function. Tissue engineering approaches have emerged for the repair of cartilage defects and damages to the subchondral bone in the early stages of OA and have shown potential in restoring the joint's function. In this approach, the use of three-dimensional scaffolds (with or without cells) provides support for tissue growth. Commercially available OC scaffolds have been studied in OA patients for repair and regeneration of OC defects. However, none of these scaffolds has shown satisfactory clinical results. This article reviews the OC tissue structure and the design, manufacturing and performance of current OC scaffolds in treatment of OA. The findings demonstrate the importance of biological and biomechanical fixations of OC scaffolds to the host tissue in achieving an improved cartilage fill and a hyaline-like tissue formation. Achieving a strong and stable subchondral bone support that helps the regeneration of overlying cartilage seems to be still a grand challenge for the early treatment of OA.
基金supported by the Versus Arthritis Research UK(Grant No:21977)European Commission via a H2020-MSCA-RISE programme(BAMOS,Grant No:734156)+1 种基金Innovative UK via Newton Fund(Grant No:102872)Engineering and Physical Science Research Council(EPSRC)via DTP CASE programme(Grant No:EP/T517793/1)。
文摘To get an optimal product of orthopaedic implant or regenerative medicine needs to follow trialand-error analyses to investigate suitable product’s material,structure,mechanical properites etc.The whole process from in vivo tests to clinical trials is expensive and time-consuming.Computational model is seen as a useful analysis tool to make the product development.A series of models for simulating tissue engineering process from cell attachment to tissue regeneration are reviewed.The challenging is that models for simulating tissue engineering processes are developed separately.From cell to tissue regeneration,it would go through blood injection after moving out the defect;to cell disperse and attach on the scaffold;to proliferation,migration and differentiation;and to the final part-becoming mature tissues.This paper reviewed models that related to tissue engineering process,aiming to provide an opportunity for researchers to develop a mature model for whole tissue engineering process.This article focuses on the model analysis methods of cell adhesion,nutrient transport and cell proliferation,differentiation and migration in tissue engineering.In cell adhesion model,one of the most accurate method is to use discrete phase model to govern cell movement and use Stanton-Rutland model for simulating cell attachment.As for nutrient transport model,numerical model coupling with volume of fluid model and species transport model together is suitable for predicting nutrient transport process.For cell proliferation,differentiation and migration,finite element method with random-walk algorithm is one the most advanced way to simulate these processes.Most of the model analysis methods require further experiments to verify the accuracy and effectiveness.Due to the lack of technology to detect the rate of nutrient diffusion,there are especially few researches on model analysis methods in the area of blood coagulation.Therefore,there is still a lot of work to be done in the research of the whole process model method of tissue engineering.In the future,the numerical model would be seen as an optimal way to investigate tissue engineering products bioperformance and also enable to optimize the parameters and material types of the tissue engineering products.
基金the National Key R&D Program of China(Nos.2021YFE0104800 and 2023YFB3812000)the General Project of Shanghai Natural Science Foundation(No.22ZR1471500)+2 种基金the International Partnership Program of Chinese Academy of Sciences(No.121631KYSB20200039)the International Cooperation Project of Shanghai Science and Technology Commission(No.20520750200)and National Center for Research and Development(Contract No.WPC2/1/SCAPOL/2021).Partial work was also financially supported by the Hengdian Group.
文摘Faraday isolators can prevent the front-end system from disturbance and damage caused by a back-reflected beam,so they are important elements in laser systems.As magneto-optical materials are the most important component in Faraday isolators,the studies on magneto-optical materials have attracted much attention these years.Tb_(3)Al_(5)O_(12)(TAG)ceramics are considered to be one of the most promising magneto-optical materials for visible to near-infrared wavelength band application because of their outstanding comprehensive magneto-optical performance.However,the optical quality of TAG ceramics needs further optimization to meet the application requirements.In this work,high optical quality(Tb_(1−x)Y_(x))_(3)Al_(5)O_(12)(x=0,0.05,0.1,0.2,and 0.3)magneto-optical ceramics were fabricated successfully by solid-state reaction sintering combined with hot isostatic pressing(HIP)post-treatment.All the ceramics obtained showed a single garnet phase for different values of x in the range studied.The addition of Y_(2)O_(3) was found to suppress the secondary phase and improve optical quality significantly.The ceramic samples obtained had clear grain boundaries and possessed the in-line transmittance values of 82.9%at 1064 nm and 82.2%at 633 nm,respectively.The Verdet constants of(Tb_(1−x)Y_(x))_(3)Al_(5)O_(12)ceramics with x=0,0.05,0.1,0.2,and 0.3 were−188.1,−175.4,−168.5,−143.0,and−119.9 rad/(T·m),respectively.The thermal conductivity of TAG ceramics was found to be 5.23 W/(m·K)at 25℃,and when 20%Y was substituted in place of Tb,the thermal conductivity decreased by only 9.4%.
基金supported by the National Natural Science Foundation of China(No.11774278)the Fundamental Research Funds for Central Universities(No.2012jdgz04).
文摘Two-dimensional(2D)tungsten selenide(WSe_(2))is promising candidate material for future electronic applications,owing to its potential for ultimate device scaling.For improving the electronic performance of WSe_(2)-based field-effect transistors(FETs),the modification of surface properties is essential.In this study,the seamless structural phase transition in WSe_(2) lattice is achieved by soft oxygen plasma,regulating the electrical conductance of WSe_(2)-based FETs.We found that during the soft oxygen plasma treatment with optimal processing time,the generated oxygen ions can substitute some selenium atoms and thus locally modify the bond length,inducing 2H→1T phase transition in WSe_(2) with seamless interfaces.The mosaic structures have been proven to tailor the electronic structure and increase the hole carrier concentration inside WSe_(2),significantly increasing the channel conductance of WSe_(2) FETs.With the further increase of the oxygen plasma treatment time,the creation of more selenium vacancy defects leads to the electronic doping,resulting in the reduction of conductance.Benefiting from the hexagonal boron nitride(h-BN)encapsulation to interrupt the partial structural relaxation from 1T to 2H phase,our WSe_(2) FET exhibits high electronic stability with conductance of 6.8×10^(-4) S,which is about four orders of magnitude higher than 2H WSe_(2)(5.8×10^(-8) S).This study could further broaden the WSe_(2) FETs in applications for functionalization and integration in electronics.
基金supported by National High-tech Research and Development Program,China(No.2018YFB1501505).
文摘Climate change is an important issue facing the world today and carbon reduction has become the fo-cus of attention for all countries.Alternative bio-fuels are an important means to achieve carbon emis-sion reduction.The production of jet fuel precursors from biomass by hydrothermal liquefaction(HTL)has received a lot of attention due to its mild conditions and environmental friendliness.Lignocellulosic biomass and algal biomass are considered as the second and the third generation biomasses as promising raw materials for alternative fuel preparation.Among them,lignocellulosic biomass has been extensively studied due to its wide range of sources and can be divided into one-step HTL and stepwise HTL accord-ing to the process method.Algal biomass has been extensively studied experimentally due to its short growth cycle and the fact that it can sequester large amounts of carbon without taking up arable land.In this paper,the feedstock composition of different biomasses is reviewed for the HTL of biomass.A detailed review of the process characteristics,reaction pathways and influencing factors for the HTL pro-duction of jet fuel precursors from lignocellulosic biomass and algal biomass is also presented.Theoretical references are provided for further process optimization and bio-crude quality upgrading.
基金the Key Project of the Natural Science Foundation of Tianjin,China(No.20JCZDJC00090).The funders played no role in the study design,data collection and analysis,decision to publish,or manuscript preparation.
文摘Inactivated coronavirus disease 2019(COVID-19)vaccines such as CoronaVac and BBIBP-CorV have been widely used in China.However,more investigation is still needed to understand antibodies'duration and effectiveness against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)variants in the real world.In this study,575 participants who had been vaccinated with two or three doses of the inactivated vaccine were recruited.Serum samples were collected and tested for anti-spike IgG and neutralizing antibodies against SARS-CoV-2(original strain,Dela,and Omicron).Unsurprisingly,a third dose of the vaccine significantly enhanced antibody responses against SARS-CoV-2 and its variants.However,despite a booster dose,the neutralizing antibody levels against Omicron,particularly the BA.5.2 subvariant,remained low.There was no sex bias,but an age bias was observed.Notably,the predominant IgG subclass antibodies were IgG1 and IgG2,with a much lower level of IgG4.After the booster shot,the ratio of IgG4 to IgG1 significantly increased.The observation of IgG1 to the IgG4 class switch after repeated inactivated vaccinations underscores the importance of continuous monitoring of subclass antibody responses.Further clinical investigations are required to understand the implications of this class switch for optimizing immunization strategies.
文摘At present,phase change materials(PCMs)with single function hardly meet the needs of advanced intelligent materials in practical applications,and the multifunction integration is the current trend.However,photo-cured multifunctional PCMs are hampered by insufficient transparency due to adding functional fillers,such as carbon and metal materials.The novel strategy is necessary to overcome this limitation.Here,a photo-cured multifunctional PCM is prepared by using the design of a lamellar structure composing the photo-cured phase change polymer layer and the functional fillers layer.The curing of the phase change polymer is realized by the photo-induced"thiol-ene"click reaction,and reversible dynamic disulfide bonds are introduced into the PCM,which not only gives the phase change crosslinked network reprocessability,but also strengthens the interface layer by the chain rearrangement to form a stable composite structure.The carboxylated multiwalled carbon nanotubes(CCNTs)and silver nanowires(AgNWs),as functional fillers,give the PCM photo-thermal conversion,self-cleaning and electromagnetic shielding(EMI SE)performances.Its phase change latent heat and photo-thermal conversion can reach 105.2 J/g and 78.5%,and the water contact angle is 142°with self-cleaning performance.In addition,due to the dense and well-developed conductive path formed by AgNWs layer on the PCM surface,the EMI SE effect can reach 39 dB with only 6.3%(in mass)filler content and 7.2%phase change latent heat loss.As far as we know,this is the first report about photo-cured PCMs with self-cleaning,photo-thermal conversion and EMI SE performances.
基金supported by Sino-Europe ALTERNATE project-China(MJ-2020-D-09).
文摘Supersonic aircraft requires thermal endurance of aviation fuel in the process of cooling engine and aircraft. As the composition of petroleum-based jet fuel (RP-3) is confined by crude oil and refining process, sustainable alternative jet fuel with green house gas reduction become to undertake the composition optimization for improving thermal stability. For designing aviation fuel with robust thermal stability and the detail understanding of thermal stability mechanism, RP-3, Fischer–Tropsch fuel, and additives with cyclic structure for absorbing free radical, were investigated thermal stability by modifying different blend ratios under different conditions. Thermal endurance degree was assessed by chroma and deposition tendency. FT blend with cyclic hydrocarbon can improve thermal endurance degree. In compliance with individual optimized blend ratio, the contribution follows methyl cyclopentane > decalin > methyl cyclohexane > tetralin > n-propyl-benzene > 1,2,4 trimethyl-benzene. The appropriate blend ratio could undertake hydrogen donors for terminating the propagation of oxygen-carrying radical, but hydrocarbons with cyclic structure could enhance deposition tendency. Methyl cyclopentane and its oxidation derivatives take the roles of solvent by anti-polymerization and hydrogen donor by opening cyclic structure in the thermal endurance process, and thus lead to a wide range of blend ratio for improving significantly thermal stability. β-scission leading to C–C bond cleavage is the major reaction at the early decomposition stage, which resulted in most abundant derivatives plus C2. The effects of additives on thermal stability are complex and nonlinear on the tendency of thermal deposits and thermal endurance degree, and thus the appropriate ANN-thermal stability model has been trained based on the experiment data and can achieve above 0.995 correlation coefficient. ANN - thermal stability model can predict not only the content of derivatives including ester, olefin, alcohol, ketone, cyclic oxide, aromatics but also the degree of thermal endurance.
基金the financial support provided by the National Natural Science Foundation of China(No.52175413)the Natural Science Foundation of Jiangsu Province(No.BK20192007)+3 种基金the National Natural Science Foundation of China for Creative Research Groups(No.51921003)the Fundamental Research Funds for the Central Universities(No.NS2021034)the Aeronautical Science Foundation of China(No.201907052002)the Interdisciplinary Innovation Fund for Doctoral Students of Nanjing University of Aeronautics and Astronautics(No.KXKCXJJ202207).
文摘Wire electrochemical machining(WECM) is a flexible and effective method for machining complex-shaped metal components, but the ability to machine large-thickness workpieces is hampered by the difficulty of transporting electrolytic products in the narrow machining gap. This paper proposes a novel hybrid machining technique that combines the characteristics of WECM and wire electric discharge machining(WEDM), namely, helical wire electrochemical discharge machining. The formation mechanism of electrical discharge in salt-glycol solution was elucidated.Experiments and simulation were conducted to verify the machining mechanism and investigate the performance of the proposed technique. The results show that as the recast layer can be removed by electrochemical action during the proposed process, the surface quality is effectively improved.Minimum surface roughness of the slit sidewall after machining reaches Ra= 0.12 μm. Minimum standard deviation of the slit after machining reaches 5 μm. Moreover, the existence of the discharges significantly improves the transport of the electrolytic products, thus ensuring high machining efficiency. In the experiments, the maximum feed rate of the helical wire electrochemical discharge machining reaches 7 μm/s(12.6 mm^(2)/min). Finally, mortise structures of Inconel 718 with good machining accuracy and surface quality are fabricated with a feed rate of 5 μm/s(9 mm^(2)/min),demonstrating that electrical discharge assisted helical wire ECM is a promising technique for machining large-thickness hard metal materials.
基金supported by the Guangxi Scholarship Fund of Guangxi Education Department,the Guangxi Med‑ical University Training Program for Distinguished Young Scholars,the Advanced Innovation Teams and Xinghu Scholars Program of Guangxi Medical University,the Guangxi Med‑ical and Health Key Discipline Construction Project,and the Science and Technology Plan Project of Qingxiu District,Nanning(Nos.2020037,2020038,2021007,2021010,and 2021012),China.
文摘Hepatocellular carcinoma(HCC)is one of the most common malignancies and a leading cause of cancer-related death worldwide.Surgery remains the primary and most successful therapy option for the treatment of early-and mid-stage HCCs,but the high heterogeneity of HCC renders prognostic prediction challenging.The construction of relevant prognostic models helps to stratify the prognosis of surgically treated patients and guide personalized clinical decision-making,thereby improving patient survival rates.Currently,the prognostic assessment of HCC is based on several commonly used staging systems,such as Tumor-Node-Metastasis(TNM),Cancer of the Liver Italian Program(CLIP),and Barcelona Clinic Liver Cancer(BCLC).Given the insufficiency of these staging systems and the aim to improve the accuracy of prognostic prediction,researchers have incorporated further prognostic factors,such as microvascular infiltration,and proposed some new prognostic models for HCC.To provide insights into the prospects of clinical oncology research,this review describes the commonly used HCC staging systems and new models proposed in recent years.
基金the financial support from the National Key R&D Program of China(2021YFB3201100)the National Natural Science Foundation of China(52172128)the Top Young Talents Programme of Xi'an Jiaotong University.
文摘Electron-correlated materials have been drawing ever-increasing attention due to their fascinating physical behaviors and extensive application scenarios.In this review,a new method for material research and design(R&D),named structural-functional unit ordering(SFU ordering),which is presented,overcomes the shortcomings—for example,the limitation of finite chemical elements and long R&D circle-of conventional strategy and thus provides guidance for the design of these high-performance functional materials on demand.Meanwhile,with the development of material characterization technologies,SFUs of different scales and types can be directly observed,which,moreover,regulate the corresponding orderings.The review,starts with an introduction of the profile for SFU ordering and the synergistic effect between SFUs.Then,studies on several new high-performance electronic-correlated materials,for example,a ferromagnetic semiconductor with local spin,ferromagnetic metals with spin topologies,ferroelectric thin films with polar topologies,piezoelectric thin films with nanopillars enclosed by charged boundaries,thermoelectric materials with local ferromagnetic nanoparticles and topotactic phase transformation with conducting nanofilaments are stated in detail one by one.The vital aspect is the breaking of local symmetry,the construction,the structure,of SFUs and their orderings existing or theoretically existing,together with the enhanced/new performance.All in all,the main comments of the review tend to the remaining challenges,promising design approaches for the SFUs,and their orderings for high-performance functional materials.